Lack of occult hepatitis B virus infection among blood donors with isolated hepatitis B core antibody living in an HBV low prevalence region of Iran

Hepatitis B virus (HBV) serological patterns among the HBsAg negative hospital attendees screened for immunization

The Hepatitis B virus (HBV) is a highly infectious virus and is endemic in Uganda. It is one of the major etiological agents for liver diseases including liver cancer. In this work, we evaluated the prevalence of the HBV serological markers and the associated socio-demographic factors among hepatitis B surface antigen (HBsAg) seronegative persons screened during routine immunization against the virus in eastern Uganda. Data on the socio-demographic characteristics were collected using a structured questionnaire, while that on the serological markers were obtained from serum samples and evaluated by using the 5-panel HBV One Step Hepatitis B Virus Combo Test Device (Fastep^R, HBV-P43M). The following markers were evaluated by the panel: HBsAg, HBsAb, HBcAb, and HBeAb. Data were analyzed using SPSS (version 26), and multinomial logistic regression was used to elicit the adjusted odds ratio. All the analysis were performed at a 95% confidence limit, and a P value ≤ 0.05 was considered significant. The 424 participants included in this study were mainly female (62.3%), married (55.4%) and aged 30 years and above (54.2%). The seropositivity of the HBsAb, HBeAb, HBcAb marker prevalence rates was 48(11.3%), 73(17.2%) and 45(10.6%) respectively. The majority of the participants (327, 77.1%) did not present with any marker. Married paricipants were significantly associated with reduced HBsAb seropositvity rate, whereas young people aged 18–29 years were associated the with increased odds of HBsAb seropositivity (p < 0.05). Male participants were significantly associated with the HBeAb and HBcAb seropositivity (p < 0.05). Similarly, contact with an HBV infected person was significantly associated with HBeAb and HBcAb seropositivity (p < 0.05). Further still, blood transfusion was significantly associated with the increased risk of HBcAb seropositivity (P < 0.05). This study has revealed a prevalence of HBV serological markers among the HBsAg seronegative persons in this community and an increased risk of transmission of the virus in the community. Our findings have key consequences pertaining the interventions that are pertinent in the control and prevention of the spread of the virus among apparently health persons.

Frequency of hepatitis B virus-DNA among hepatitis B surface-Ag negative, anti-hepatitis B core antibody-positive blood donors in Yazd, Iran

BACKGROUND:

The diagnosis of hepatitis B infection in most blood transfusion centers is based on hepatitis B surface (HBs) antigen detection by an enzyme immunoassay method. This study aimed to determine the frequency of hepatitis B core (HBc) antibody, HBs antibody, and hepatitis B virus (HBV) DNA among HBs antigen-negative healthy blood donors of Yazd province, Iran.

MATERIALS AND METHODS:

This cross-sectional study was conducted on 1500 healthy blood donor samples negative for HBs antigen, hepatitis C virus antibody, human immunodeficiency virus antigen/antibody, and rapid plasma regain tests. All samples were screened for HBc antibody test. HBs antibody and real-time polymerase chain reaction were performed for HBc antibody-positive samples.

RESULTS:

HBc antibody was positive in 74 (4.9%) samples and 11 (14.9%) of 74 positive samples for HBc antibody were negative for HBs antibody. Sixty-three (85.1%) positive samples for HBc antibody had HBs antibody titer over 10 IU/L, and 43 (58.1%) had HBs antibody titer over 100 IU/L. There was no hepatitis B DNA-positive sample in the present study.

CONCLUSIONS:

The study results suggest that there is a very low risk for transmission of HBV through blood donors of Yazd, Iran.

Prevalence of HBV and HCV Infections in Iranian Blood Donors; An Updated Systematic Review and Meta-Analysis

BACKGROUND Awareness of the prevalence of hepatitis B (HBV) and hepatitis C virus (HCV) infections, as blood transmitted infections, among blood donors can help policymakers improve the guidelines, share experiences, and estimate the blood safety over the country and in the region. We aimed to determine the prevalence of HBV and HCV infection in Iranian blood donors based on the present published literature. METHODS A meta-analysis was carried out based on the results of an electronic literature search in the international and national databases for all articles published until October 2020. We selected studies that had appropriate sampling and valid statistical analysis as well as proper measurement methods. The heterogenic indices of the studies were determined using Cochran's (Q) and I-square (I2) tests. According to the heterogeneity results, a fixed or random-effects model was implemented to estimate the pooled prevalence of HBV and HCV. Meta-regression was conducted to explore the suspected sources of heterogeneity. RESULTS We included 61 and 58 eligible studies related to HBV and HCV, respectively. The pooled prevalence of HBV was 0.57% (95% confidence interval (CI): 0.47 - 0.67, I2: 99.9%) among the blood donors. The range of prevalence rates of HBV was between 0.10% and 2.34% in different areas of Iran. The pooled prevalence of HCV was 0.22% (95% CI: 0.20 - 0.24, I2: 98.64%) in blood donors, which varied between 0.02% and 1.09% in separate locations. Subgroup and meta-regression analyses revealed that the year of publication, geographical location, and quality of the studies probably generated the heterogeneity. CONCLUSION The prevalence of HBV and HCV decreased steadily in Iranian blood donors during the past two decades. It should be asserted that most of the health policies and safety measures taken in recent years in Iran have been effective and promising.

Prevalence of occult HBV infection in Western countries

Due to a lack of standardized tests, it is difficult to obtain prevalence data and define the real impact of occult HBV infection (OBI) in Western countries. The present review article addresses the prevalence of OBI, defined as presence of hepatitis B virus (HBV) DNA in liver tissue or plasma in HBsAg-negative subjects, in Western countries. This varies in different studies according to the different methodologies used (based on serology vs virology), to the sample analyzed for the diagnosis (liver tissue vs plasma), to the different populations studied, to the different geographical variations in the HBV spread, to the host characteristics (age, gender, risk factors for acquiring HBV infection) and to the presence of other parenteral infections (hepatitis C virus and/or human immunodeficiency virus [HIV] infections). Considering the different liver diseases analyzed, that is in patients with cryptogenic cirrhosis or advanced liver fibrosis, the prevalence of OBI ranges 4% to 38%. Considering the different populations studied, in the case of parenteral blood exposure it is about 45%, in patients with chronic hepatitis C it is estimated at about 52%, in HIV-infected patients it ranges from 0% to 45%, in blood donors from 0% to 22.7% and in hemodialysis patients it ranges from 0% to 54%. In conclusion, OBI is a virological entity to be considered when performing the patient's evaluation for immunosuppressive diseases, liver pathologies, or for blood transfusions. Knowing the prevalence and clinical impact of OBI will allow better patient management.

Epidemiology, risk factors, and molecular characterization of occult hepatitis B infection among anti-hepatitis B core antigen alone subjects

OBJECTIVES

Features of occult hepatitis B virus (HBV) infection among the anti-hepatitis B core antigen (anti-HBc) positives have yet to be described in more details. This study aimed to determine the molecular prevalence of occult HBV infection (OBI), and association to risk factors among seropositives for anti-HBc.

METHODS

This was part of a community-based screening project that included 5234 cases. All participants completed a questionnaire on demographic and socio-epidemiological information. Then, the blood samples were collected and tested for anti-HBc and HBsAg using ELISA method. To identify OBI, nested-polymerase chain reaction (PCR) assays were performed for HBV-S and X genes, and viral load was determined using an in-house real-time PCR. Sequencing and phylogenetic analysis have been implemented for genotyping.

RESULTS

Overall, 596 cases, positive only for anti-HBc were included in the study. OBI was detected among 61 cases (10.2%). The genotype and subgenotype of HBV among all of them was D1, except one that was D4. Most of them had low viral loads ranged from 1.2 × 10² to 1.34 × 10 ³  copies/mL; 19.6% had undetectable viral loads. Important mutations in surface protein and reverse transcriptase were sI92T, sQ129H, rtL80I, rtS85F, rtL91I. The prevalence of OBI was related to some risk factors, such as tattooing (P = 0.02), sexual activities (P = 0.009), and diabetes (P = 0.031).

CONCLUSION

Our study suggests that OBI should be considered among anti-HBc seropositive subjects. This form of HBV infection was accompanied with some mutations, risk factors, and diseases. However, further investigations are needed to determine virological importance of documented mutations.

The epidemiology of hepatitis C virus in Iran: Systematic review and meta-analyses

The aim of this study was to characterize hepatitis C virus (HCV) epidemiology in Iran and estimate the pooled mean HCV antibody prevalence in different risk populations. We systematically reviewed and synthesized reports of HCV incidence and/or prevalence, as informed by the Cochrane Collaboration Handbook, and reported our findings following the PRISMA guidelines. DerSimonian-Laird random effects meta-analyses were implemented to estimate HCV prevalence in various risk populations. We identified five HCV incidence and 472 HCV prevalence measures. Our meta-analyses estimated HCV prevalence at 0.3% among the general population, 6.2% among intermediate risk populations, 32.1% among high risk populations, and 4.6% among special clinical populations. Our meta-analyses for subpopulations estimated HCV prevalence at 52.2% among people who inject drugs (PWID), 20.0% among populations at high risk of healthcare-related exposures, and 7.5% among populations with liver-related conditions. Genotype 1 was the most frequent circulating strain at 58.2%, followed by genotype 3 at 39.0%. HCV prevalence in the general population was lower than that found in other Middle East and North Africa countries and globally. However, HCV prevalence was high in PWID and populations at high risk of healthcare-related exposures. Ongoing transmission appears to be driven by drug injection and specific healthcare procedures.

Prevalence of antibody to hepatitis B core antigen among hepatitis B surface antigen-negative blood donors in Ilorin, Nigeria: A cross-sectional study

BACKGROUND

Post-transfusion hepatitis occurs even with stringent donor selection criteria and screening for hepatitis B surface antigen (HBsAg). The objective of this study was to determine the prevalence of antibody to hepatitis B core antigen (anti-HBc) in HBsAg-negative blood donors.

METHODS

This was a cross-sectional study in which 200 HBsAg-negative blood donors were recruited. Screening for viral markers was done using both a rapid test kit and enzyme-linked immunosorbent assay (ELISA) for anti-HBc IgM. Quantitative and qualitative analysis of anti-HBc IgM was done by "capture" enzyme immunoassay using DIA.PRO HBc IgM test kits. The other viral markers were investigated using one step cassette style HBV tests. SPSS version 16 was used for data analysis. A P-value of 0.05 or less was considered significant.

RESULTS

There were 190 male (95%) and 10 female (5%) blood donors, with a mean age of 31.7 ± 7.9 years. The prevalence of anti-HBc IgM was 4%. The other viral markers (HBeAg, anti-HBeAg, anti-HBs and total anti-HBc) had a prevalence of 1.5%, 23%, 2.5%, and 32.5%, respectively.

CONCLUSIONS

The prevalence of anti-HBc IgM in this study was high, and this supports the fact that screening blood donors for HBsAg alone is not sufficient to prevent transmission of HBV.

Prevalence and characterization of occult hepatitis B infection among blood donors in central Saudi Arabia

OBJECTIVES

To evaluate the prevalence of occult hepatitis B viral infections (OBIs)  among blood donors considering the clinical and epidemiological importance of identifying OBIs.

METHODS

A cross-sectional study conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2011 and January 2012. Blood donors (n=8501) were screened for Hepatitis B virus surface antigen (HBsAg) and hepatitis B core antibodies (HBcAb). All HBsAg-negative and HBcAb-positive samples were tested further for hepatitis B surface antibodies (HBsAb), hepatitis B virus (HBV)-DNA, and HBV genotyping.  

RESULTS

Of the 8501 serum samples tested, 56 (0.7%) were positive and 8445 (99.3%) were negative for HBsAg. Among the HBsAg-negative samples, 198 (2.3%) were positive for HBcAb and these patients were suspected to have OBIs. Among the HBcAb-positive samples, 119 (60.1%) were positive while 79 (39.9%) were negative for HBsAb. Analysis of HBV-DNA for the suspected OBIs showed that 17 out of 198 samples (8.6%) yielded positive results, and all of them were HBsAb-negative. The viral load was low (less than 20-186 IU/mL) in all OBIs. Hepatitis B virus genotyping showed that 15 out of 17 samples (88.2%) were genotype D, and the other 2 samples (11.8%) were genotype E. 

CONCLUSION

The prevalence of OBIs among blood donors in Riyadh was 0.2%. Therefore, it is recommended that HBV molecular testing should be incorporated with serological assays for screening of blood donors.

Prevalence of antibody to Hepatitis B core antigen and Hepatitis B virus DNA in HBsAg negative healthy blood donors

Background

Hepatitis B virus is one of the most important blood born viruses. Although the sensitivity of screening tests has been considerably increased, transmission may still occur due to window period or occult hepatitis B infections (OBIs). This study was aimed at evaluating the prevalence of the anti-HBc and identifying the HBV DNA in HBsAg negative blood donors.

Methods

The Blood samples from 2031 HBsAg-negative blood donors were divided into three aliquots and tested for anti-HBc, anti-HBs and HBV DNA. Serologic screening including anti-HBc and anti-HBs was performed. As a confirmatory test, all positive results for anti-HBc were retested with another kit. Two positive results were considered for anti-HBc positivity. All HBsAg negative selected donations were tested by PCR assay on pooled specimens (five samples per pool), plasma samples found to be HBsAg negative but anti-HBc positive were selected for a single-unit specimen Real-Time assay.

Results

The study population had a mean age of 33.25 ± 10.09 years were mainly composed of males (94.8 %). The seroprevalance rate was 4.9 % for Anti-HBc and 31.9 % for HBsAb. The majority (58.6 %) of Anti-HBc positive cases were regular blood donors with 42–49 years being the largest age group (41.4 %). Neither individual NAT nor pooled NAT test detected any HBV DNA.

Conclusion

However, Screening of anti-HBc Ab is proposed as a method to identify previous contact with HBV, but there is controversy in literature data regarding the cost-benefit of exclusion of positive anti-HBc Ab in blood donors. Our data does not suggest HBc-Ab test as a screening tool in the study setting.

Hepatitis B surface gene variants isolated from blood donors with overt and occult HBV infection in north eastern Egypt

Background

Major hydrophilic region in genomic HBV extending from aa99 to aa169, clustered with a highly conformational epitope, is critical to the antigenicity of hepatitis B surface antigen (HBsAg) and may affect the diagnosis of HBV in HBV screening test. So, this study aimed to characterize variants of S gene product of hepatitis B virus (HBV) isolated from patients with overt or occult HBV infection in north-eastern Egypt.

Methods

The study included sera of two different groups of volunteer blood donors (VBDs), 82 with overt HBV that were positive for HBsAg and anti-HBc and 343 donors negative for HBsAg eligible for donation. Of the latter group, only 44 were positive for anti-HBc. All anti-HBc positive sera were subjected to HBV DNA detection and partial sequence analysis targeting the HBV S gene.

Results

HBV DNA was detected in 22.7 % of HBsAg-/anti-HBc + (10/44 patients) and in 90 % of HBsAg + donors (74/82 patients) with significant statistical difference (P = 0.0001). Phylogenetic analysis showed that HBV strains retrieved from both groups were of genotype D. Amino acid escape mutation T125M was detected in only 2 samples of the occult infection group and in none of the overt group (P = 0.01). Different amino acid substitutions were identified in overt infection group: S143L/T (16.2 %, 12/74) and P120T/S (2.7 %, 2/74). Q129R was significantly more frequent in cases with occult HBV infection (40 %, 4/10) than overt group (6.8 %, 5/74) (P = 0.01).

Conclusions

HBV genotype D predominated both in patients with overt and occult HBV infection. Different profiles of amino acid substitutions in the major hydrophilic region were seen in these two groups in Egypt.

Occult hepatitis B infection in patients with cryptogenic liver cirrhosis in southwest of iran

Background:

Chronic hepatitis B virus (HBV) infection has a broad spectrum of manifestation, ranging from silent carrier state to advanced cirrhosis and hepatocellular carcinoma. The persistence of HBV DNA in serum and hepatocytes of the cirrhotic patient could be detected by molecular techniques in spite of negative HBV serologic markers.

Objectives:

This case-control study was designed to evaluate the prevalence of occult HBV infection (OBI) in patients with cryptogenic liver cirrhosis in comparison with healthy subjects.

Patients and Methods:

Of 165 patients with liver cirrhosis, 50 consecutive patients with cryptogenic cirrhosis and 80 healthy individual without any risk factors as a control group were enrolled in this study. Their sera were tested for HBV DNA using nested PCR method.

Results:

Of 50 patients with cryptogenic cirrhotic, 36 (72%) were male. The mean age of patients was 53.34 ± 14.73 years; 80 healthy subjects were selected as control group with mean age of 32.65 ± 8.51 years; 7 (14%) of the patients with cryptogenic cirrhosis showed positive HBV DNA by PCR, while HBV DNA was negative for the control group (P = 0.0001); 4 (57%) cases with positive HBV shown by PCR were negative for anti-HBc and anti-HBs tests. The mean level of transaminases was significantly higher in patients with cirrhosis. There were no significant differences in demographic parameters, transaminases level and degree of hepatic failure among cirrhotic patients with and without OBI.

Conclusions:

The prevalence of OBI was relatively high in patients with cryptogenic cirrhosis. OBI was found among the patients above 40 years old. Prospective cohort studies are needed to evaluate the clinical significance of OBI.

The prevalence of isolated hepatitis B core antibody and its related risk factors among male injected drug users in Isfahan prisons

Background:

The prevalence of isolated hepatitis B core antibody (anti-HBc) varies between 1% and 30% in different populations. Isolated anti-HBc-positive patients who suffer from occult hepatitis B virus (HBV) infection have the potential to transmit HBV infection. So isolated anti-HBc screening is a valuable tool to prevent HBV transmission. Considering the importance of isolated anti-HBc screening and high prevalence of HBV among injected drug users (IDU) prisoners, we designed this study to evaluate the isolated anti-HBc positivity among inmates with the history of IDU in our area.

Materials and Methods:

We did this cross-sectional study from September 2009 to March 2010 among volunteer male IDU prisoners in Isfahan. Blood samples were taken from all of subjects and tested for HBV markers. Then a questionnaire containing socio-demographic, drug histories and high risk behaviors information was completed for all participants. Data analysis was done utilizing univariate analysis and multiple logistic regressions. A P < 0.05 was considered significant.

Results:

Totally 970 male IDU prisoners (mean age 32.6 ± 8.1) were included in our study. The prevalence of isolated HBc Ab was 4.5%. Isolated anti-HBc significantly was related to tooth filling (OR: 2.62, CI: 1.20-7.14) and imprisonment (OR: 3.95, CI: 1.39-11.18). We couldn’t find any relationship between isolated anti-HBc positivity and addiction duration, incarceration frequency, recent incarceration duration or number of injection per month.

Conclusion:

For screening high risk groups in parallel with hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb) and other viral markers, maybe it is better to check HBcAb too, because isolated HBcAb-positive patients may have occult hepatitis B infection which could transfer the infection to others.

Isolated anti-hbc and occult HBV infection in dialysis patients

BACKGROUND

Occult Hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV-DNA in the liver or serum with undetectable hepatitis B surface antigen (HBsAg). Hemodialysis (HD) patients are at risk of acquiring parenterally transmitted infections.

OBJECTIVES

The aim of this study was to assess the prevalence of OBI in HD patients.

PATIENTS AND METHODS

A hundred HBsAg negative HD patients were included in this study from main dialysis units in Tehran, Iran. HBsAg, hepatitis B surface antibody (anti-HBs), hepatitis B core antibody (anti-HBc) and liver enzymes levels were examined in all subjects. The presence of HBV-DNA was determined in plasma samples using real-time PCR.

RESULTS

A hundredpatients with a mean age of 58.5 ± 16.1 years were enrolled in this study. In total, 56.7% were male and 43.3% female. Anti-HBs, anti-HBc, anti-HCV and anti-HIV were detected in 56.7%, 2%, 5.2% and 1% of patients, respectively. Isolated anti-HBc was detected in 2% of cases. HBV-DNA was detected in 1% of HBsAg negative patients.

CONCLUSIONS

This study showed a low rate of isolated anti-HBc and occult HBV infection in HD patients. It can be due to improvement of people's knowledge about HBV transmission routes, HBV vaccination of HD patients and regular surveillance of HBV infection.

Occult HBV infection in Morocco: from chronic hepatitis to hepatocellular carcinoma

BACKGROUND & AIMS

Morocco is one of low to intermediate endemic areas for hepatitis B virus (HBV) infection, but no reports have been published on Occult HBV infection (OBI). To determine the prevalence of OBI and its clinical impact among patients with cryptogenic and HCV-related chronic liver disease in Morocco.

METHODS

A total of 152 HBsAg-negative patients (60 patients with cryptogenic hepatitis and 92 HCV carriers) were enrolled in this study. Sera collected from all patients were tested for anti-HBc and anti-HBs antibodies. OBI was assessed in serum and liver tissue samples using highly sensitive PCR assays targeting Surface, X and core regions of the HBV genome and confirmed by Southern blot hybridization.

RESULTS

A high rate of anti-HBc positivity was found among patients with HCV infection (57/92, 61.95%) compared to those with cryptogenic hepatitis (24/60, 40%) (P = 0.034). A high prevalence of OBI was found among patients with HCV infection (42/92, 45.65%) compared to those with cryptogenic hepatitis (17/60, 28.3%) (P = 0.013). In both groups, the prevalence of OBI increased in parallel with advancing stage of liver disease (χ2 = 6.73; P = 0.0095). The highest proportion of OBI was reached among HCV-related HCC cases (62.5%). Multivariate Cox regression analysis revealed that older age (≥56 years), positivity for anti-HBc and presence of OBI were independent risk factors for the development of HCC in HCV-infected patients.

CONCLUSION

This study helps to understand the current status of OBI and its impact on the severity of liver disease in Moroccan patients.

Viral hepatitis and HIV infection among injection drug users in a central Iranian City

OBJECTIVE

This study aimed to determine the prevalence of serological markers for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and occult HBV infection among injection drug users (IDUs) with isolated anti-hepatitis B core (anti-HBc).

METHODS

A total of 153 male IDUs were tested for anti-hepatitis B surface (anti-HBs), hepatitis B surface antigen (HBsAg), anti-HBc, anti-HCV, and anti-HIV. The presence of HBV-DNA was determined in plasma samples of individuals with isolated anti-HBc (HBsAg negative, anti-HBs negative, and anti-HBc positive) by polymerase chain reaction (PCR).

RESULTS

The prevalence of markers for viral hepatitis and HIV infections was 59.5% for anti-HCV, 44.4% for anti-HBs, 22.9% for anti-HBc, 7.2% for HBsAg, and 5.9% for anti-HIV. Several markers for coinfection, including HBV-HCV (5.9%), HCV-HIV (5.2%), HBV-HIV (2.0%), and HBV-HCV-HIV (1.3%), were present. Of the 7.2% of IDUs with isolated anti-HBc, all were anti-HCV positive and 18.2% were anti-HIV positive; however, no cases had detectable HBV-DNA as a marker of occult infection.

CONCLUSIONS

Markers for HCV, HBV, HIV, and combinations of these infections were common among IDUs in a city of central Iran. Isolated anti-HBc was associated with HCV but not with occult HBV infection in this sample. The 10-fold higher prevalence of HCV than HIV infection may be a harbinger of increasing HIV among IDUs in this area.

Hepatitis B viral DNA among HBs antigen negative healthy blood donors

BACKGROUND

Presence of occult hepatitis B infection (OBI) renders HBs antigen (HBsAg) undetectable by ELISA. Therefore it is valuable to evaluate the frequency of OBI among healthy blood donors to improve and perhaps change the strategies of blood screening to reduce the risk of HBV transmission.

OBJECTIVES

The aim of this study was to determine the presence of HBcAb and HBV DNA among Iranian HBsAg negative healthy blood donors who donated their blood to the Tehran Blood Transfusion Center during 2011.

PATIENTS AND METHODS

1000 serum specimens negative for HBsAg, HCV antibody and HIV antibody were collected from healthy blood donors and tested for HBcAb. Presence of hepatitis B viral DNA was checked in HBcAb positive samples by nested PCR with two sets of primers to amplify part of HBV S gene.

RESULTS

There were 64 women and 936 men in the population under study. The mean ± SD age of the donors was 38 ± 11 years. 80 out of 1000 samples (8%) were found to be positive for HBcAb. HBV DNA was detected in 50% of HBcAb positive specimens. The mean ± SD age of donors without HBV DNA was 37.7 ± 10.5 years and for donors with HBV DNA was 40.9 ± 11.2 years (P = 0.05).

CONCLUSIONS

OBI was prevalent among 50% of HBcAb positive healthy blood donors. The frequency of positive HBcAb among healthy HBsAg negative blood donors was comparable to previous studies reported from Iran. On the other hand, the frequency of HBV DNA in HBsAg negative blood donors was higher than previous reports.

Frequency of hepatitis B virus DNA in anti-HBc positive, HBsAg negative blood donors in Rasht, northern Iran

BACKGROUND

One of the important factors in the ensuing safety of blood transfusion is to use a sensitive screening assay for detection of blood-born infective agents such as HBV which transmits through transfusion. To improve the detection rate of HBV infection in blood donors, a cross-sectional study was conducted in Rasht, which is the largest city in the north of Iran to explore the possibility of using anti-HBc as a screening test.

STUDY DESIGN AND METHODS

A total of 2041 blood samples negative for HBsAg, Anti-HCV, Anti-HIV I, II and RPR were tested to detect anti-HBc and then the positive anti-HBc samples were further checked for the presence of HBV DNA.

RESULTS

The prevalence of anti-HBc positive samples was 3.8% and HBV DNA was detected in only one sample.

CONCLUSIONS

This study showed that anti-HBc positive blood donors may be a source of HBV transmission and further study for evaluation of HBV DNA in anti-HBc positive blood units is needed.

Hepatitis B virus in transfusion medicine: still a problem?

Hepatitis B virus (HBV) has probably evolved with humans for nearly 35,000 years. HBV diversified into 9 genotypes (A-I) presenting specific features directing epidemiology, clinical expression and testing. Genotypes E and C are more infectious and carry higher risk of chronicity and cancer. HBsAg blood screening implemented 40 years ago enormously decreased the risk of transfusion transmission but the remaining risk requires extremely sensitive nucleic acid testing (NAT) to be removed. Limitations of the host immune system, the impact of immunodeficiency and the mechanisms utilised for viral persistence were recently identified. HBV replication produces excess HBsAg and infectious and defective viral particles but screening assays for HBsAg or viral particles alone do not allow fully efficient detection, making necessary screening for both. The host immune system fails to completely control the virus that escapes and persists unrecognized at very low levels or as immuno-selected variants. Variants may not be identified by assays, explaining false negative results. Specific mutations may affect post-transcriptional mechanisms including HBV RNA splicing. Asymptomatic HBV infected blood donors are at risk of long-term complications through mechanisms to be understood for appropriate counselling. Infectivity of occult HBV infection (OBI) by transfusion appears low, anti-HBc (anti-core antigen) only being more infectious than anti-HBs (anti-S protein) positive units.